Thermal expansion groove of a capacitive touch system

ABSTRACT

An apparatus may include a touch sensor where the touch sensor has a first set of electrodes and a second set of electrodes that are electrically isolated from the first set of electrodes, a shield layer positioned adjacent to the touch sensor, and the shield layer having a plurality of thermal expansion grooves.

CROSS REFERENCE TO RELATED APPLICATIONS

The present Application is a Continuation-in-Part of U.S. patentapplication Ser. No. 17/665,699 by Jon Bertrand et al entitled “Shieldfor a Capacitive Touch System,” filed on Feb. 7, 2022. U.S. patentapplication Ser. No. 17/665,699 is a Continuation of U.S. patentapplication Ser. No. 16/713,677 by Jon Bertrand et al., entitled “RadioFrequency Transparent Capacitive Touch Systems and Methods,” filed onDec. 13, 2019. U.S. patent application Ser. No. 16/713,677 claimspriority to U.S. Provisional Patent Application No. 62/794,392 by JonBertrand et al., entitled “Radio Frequency Transparent Capacitive TouchSystems and Methods,” filed on Jan. 18, 2019. Each of these applicationsare assigned to the assignee hereof, and expressly incorporated byreference herein.

FIELD OF THE DISCLOSURE

This disclosure relates generally to capacitive sensors, such as a touchpad, touch screen, a proximity sensor, or another type of touchcapacitive sensor, and methods of operation. More particularly, thisdisclosure relates to systems and methods with a thermal expansiongroove incorporated into the shield layer of a capacitance touch sensor.

BACKGROUND

Touch pads are often included on processor-based devices, such as laptopcomputers or the like, in order to allow a user to use fingers, styli,or the like as a source of input and selection. However, capacitivetouch pads often require electrical shielding to prevent noise from theprocessor-based device from interfering with normal touch pad functions.

SUMMARY

In some embodiments, an apparatus may include a touch sensor where thetouch sensor has a first set of electrodes and a second set ofelectrodes that are electrically isolated from the first set ofelectrodes, a shield layer positioned adjacent to the touch sensor, andthe shield layer having a plurality of thermal expansion grooves.

At least a first thermal expansion groove may be transversely orientedwith respect to a second thermal expansion groove.

At least a first thermal expansion groove may be segmented and extendfrom a first region proximate a first side of the shield layer to asecond region proximate a second side of the shield layer where thefirst side is opposite to the second side.

Segments of the first thermal expansion groove may be separated bytracts of electrically conductive material that form the shield layer.

A first set of tracts of the first thermal expansion groove may bearranged to line up with a second set of tracts of a second thermalexpansion groove where the second thermal expansion groove may bealigned with the first thermal expansion groove.

A first set of tracts of the first thermal expansion groove may beoffset from a second set of tracts of a second thermal expansion groovewherein the second thermal expansion groove may be aligned with thefirst thermal expansion groove.

A first thermal expansion groove may be formed in a tract betweensegments of a second thermal expansion groove.

The apparatus may include an intersection between the first thermalexpansion groove and the second thermal expansion groove that is alignedwith an anti-node formed between the first set of electrodes and thesecond set of electrodes of the touch sensor.

At least one of the thermal expansion grooves may align with ananti-node of the electrodes of the touch sensor.

At least one of the thermal expansion grooves may be offset from eitherthe first set of electrodes or the second set of electrodes of the touchsensor.

At least one of the thermal expansion grooves may be formed in an edgeof at least one side of the shield layer.

A first set of thermal expansion grooves may be aligned with each otherand may be substantially equidistantly spaced along a first dimension ofthe shield layer.

A second set of thermal expansion grooves may be aligned with each otherand may be substantially equidistantly spaced along a second dimensionof the shield layer where the second set of thermal expansion groovesare transversely oriented with respect to the first set of thermalexpansion grooves.

In some embodiments, an apparatus may include a touch sensor where thetouch sensor having a first set of electrodes and a second set ofelectrodes that are electrically isolated from the first set ofelectrodes, a shield layer positioned adjacent to the touch sensor, andthe shield layer having a plurality of segmented thermal expansiongrooves.

At least a first thermal expansion groove may be transversely orientedwith respect to a second thermal expansion groove.

Segments of the first thermal expansion groove may be separated bytracts of electrically conductive material that form the shield layer.

At least one of the thermal expansion grooves may align with ananti-node of the electrodes of the touch sensor.

At least one of the thermal expansion grooves may be offset from eitherthe first set of electrodes or the second set of electrodes of the touchsensor.

At least one of the thermal expansion grooves may be formed in an edgeof at least one side of the shield layer.

In some embodiments, an apparatus may include a touch sensor where thetouch sensor having a first set of electrodes and a second set ofelectrodes that are electrically isolated from the first set ofelectrodes, a shield layer positioned adjacent to the touch sensor, theshield layer having a plurality of thermal expansion grooves, a firstthermal expansion groove of the plurality is transversely oriented withrespect to a second thermal expansion groove of the plurality, a firstthermal expansion groove is segmented and extends from a first regionproximate a first side of the shield layer to a second region proximatea second side of the shield layer, wherein the first side is opposite tothe second side, the segments of the first thermal expansion groove areseparated by tracts of electrically conductive material that form theshield layer, the first thermal expansion groove is formed in a tractbetween segments of a second thermal expansion groove, and the first andsecond thermal expansion grooves aligns with an anti-node of theelectrodes of the touch sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example of a computing device in accordance with thedisclosure.

FIG. 2 depicts an example of a touch controller in accordance with thedisclosure.

FIG. 3 depicts an example of a touchpad in accordance with thedisclosure.

FIG. 4 depicts an example of a touchpad in accordance with thedisclosure.

FIG. 5 depicts an example of a touchpad shield in accordance with thedisclosure.

FIG. 6 depicts an example of a touchpad shield in accordance with thedisclosure.

FIG. 7 depicts an example of a touchpad shield in accordance with thedisclosure.

FIG. 8 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 9 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 10 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 11 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 12 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 13 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 14 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 15 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 16 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 17 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 18 depicts an example of a shield structure in accordance with thedisclosure.

FIG. 19 depicts an example of a method for transmitting a wirelesssignal in accordance with the disclosure.

FIG. 20 depicts an example of a shield layer in accordance with thedisclosure.

FIG. 21 depicts an example of a touch sensor and a shield layer inaccordance with the disclosure.

FIG. 22 depicts an example a shield layer in accordance with thedisclosure.

FIG. 23 depicts an example a shield layer in accordance with thedisclosure.

FIG. 24 depicts an example of an arrangement of thermal expansiongrooves in a shield layer in accordance with the disclosure.

FIG. 25 depicts an example of an arrangement of thermal expansiongrooves in a shield layer in accordance with the disclosure.

FIG. 26 depicts an example of an arrangement of thermal expansiongrooves in a shield layer in accordance with the disclosure.

FIG. 27 depicts an example of an arrangement of thermal expansiongrooves in a shield layer in accordance with the disclosure.

FIG. 28 depicts an example of an arrangement of thermal expansiongrooves in a shield layer in accordance with the disclosure.

FIG. 29 depicts an example of an arrangement of thermal expansiongrooves in a shield layer in accordance with the disclosure.

While the disclosure is susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and will be described in detail herein. However,it should be understood that the disclosure is not intended to belimited to the particular forms disclosed. Rather, the intention is tocover all modifications, equivalents and alternatives falling within thespirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

This description provides examples, and is not intended to limit thescope, applicability or configuration of the invention. Rather, theensuing description will provide those skilled in the art with anenabling description for implementing embodiments of the invention.Various changes may be made in the function and arrangement of elements.

Thus, various embodiments may omit, substitute, or add variousprocedures or components as appropriate. For instance, it should beappreciated that the methods may be performed in an order different thanthat described, and that various steps may be added, omitted, orcombined. Also, aspects and elements described with respect to certainembodiments may be combined in various other embodiments. It should alsobe appreciated that the following systems, methods, devices, andsoftware may individually or collectively be components of a largersystem, wherein other procedures may take precedence over or otherwisemodify their application.

For purposes of this disclosure, the term “aligned” generally refers tobeing parallel, substantially parallel, or forming an angle of less than35.0 degrees. For purposes of this disclosure, the term “transverse”generally refers to perpendicular, substantially perpendicular, orforming an angle between 55.0 and 125.0 degrees. For purposes of thisdisclosure, the term “length” generally refers to the longest dimensionof an object. For purposes of this disclosure, the term “width”generally refers to the dimension of an object from side to side and mayrefer to measuring across an object perpendicular to the object'slength.

For purposes of this disclosure, the term “electrode” generally refersto a portion of an electrical conductor intended to be used to make ameasurement, and the terms “route” and “trace” generally refer toportions of an electrical conductor that are not intended to make ameasurement. For purposes of this disclosure in reference to circuits,the term “line” generally refers to the combination of an electrode anda “route” or “trace” portions of the electrical conductor. For purposesof this disclosure, the term “Tx” generally refers to a transmit line,and the term “Rx” generally refers to a sense line.

It should be understood that use of the terms and “touch sensor”throughout this document may be used interchangeably with “capacitivetouch sensor,” “capacitive sensor,” “capacitive touch and proximitysensor,” “proximity sensor,” and “touch and proximity sensor.” Such atouch sensor may be incorporated into a touch panel, a computing device,a touch screen, a touch pad, a mobile device, an electronic tablet, aphone, another electronic device, or combinations thereof. The touchsensor may be incorporated into a stack of layers that also include ashield layer, component layer, blank layers, other types of layers, orcombinations thereof. In some cases, the touch sensor may be one of thelayers of the stack or compose multiple layers of the stack.

It should also be understood that, as used herein, the terms “vertical,”“horizontal,” “lateral,” “upper,” “lower,” “left,” “right,” “inner,”“outer,” etc., can refer to relative directions or positions of featuresin the disclosed devices and/or assemblies shown in the Figures. Forexample, “upper” or “uppermost” can refer to a feature positioned closerto the top of a page than another feature. These terms, however, shouldbe construed broadly to include devices and/or assemblies having otherorientations, such as inverted or inclined orientations wheretop/bottom, over/under, above/below, up/down, and left/right can beinterchanged depending on the orientation.

FIG. 1 depicts an example of a portable electronic device 100. In thisexample, the portable electronic device is a laptop. In the illustratedexample, the portable electronic device 100 includes input components,such as a keyboard 102 and a touch pad 104. The portable electronicdevice 100 also includes a display 106. A program operated by theportable electronic device 100 may be depicted in the display 106 andcontrolled by a sequence of instructions that are provided by the userthrough the keyboard 102 and/or through the touch pad 104. An internalbattery (not shown) may be used to power the operations of the portableelectronic device 100.

The keyboard 102 includes an arrangement of keys 108 that can beindividually selected when a user presses on a key with a sufficientforce to cause the key 108 to be depressed towards a switch locatedunderneath the keyboard 102. In response to selecting a key 108, aprogram may receive instructions on how to operate, such as a wordprocessing program determining which types of words to process. A usermay use the touch pad 104 to give different types of instructions to theprograms operating on the electronic device 100. For example, a cursordepicted in the display 106 may be controlled through the touch pad 104.A user may control the location of the cursor by sliding his or her handalong the surface of the touch pad 104. In some cases, the user may movethe cursor to be located at or near an object in the computing device'sdisplay and give a command through the touch pad 104 to select thatobject. For example, the user may provide instructions to select theobject by tapping the surface of the touch pad 104 one or more times.

The touch pad 104 may include a capacitance sensor disposed underneath akeyboard housing (i.e., the surface containing the keyboard 102). Insome examples, the touch pad 104 is located in an area of the keyboard'ssurface where the user's palms may rest while typing. In some cases, thetouch pad is visual through an opening formed in the key board housing.In other examples, the touch pad is located underneath the keyboard andtouches to the areas of the keyboard housing that are positioned overthe touch pad may be detected by the touch pad. In such examples wherethe keyboard housing functions as the touch surface of the touch pad,the keyboard housing may have at least a section adjacent to the touchpad stack that is electrically non-conductive to allow electricalsignals to be detected on the touch pad. In some examples, a section ofkeyboard housing that is electrically non-conductive may include a glassmaterial, a plastic material, a dielectric material, another type ofmaterial, or combinations thereof.

The capacitance sensor may include a printed circuit board that includesa first layer of electrodes oriented in a first direction and a secondlayer of electrodes oriented in a second direction that is transversethe first direction. These layers may be spaced apart and/orelectrically isolated from each other so that the electrodes on thedifferent layers do not electrically short to each other. Capacitancemay be measured at the overlapping intersections between the electrodeson the different layers. However, as the user's finger or otherelectrically conductive objects approach the intersections, thecapacitance may change. These capacitance changes and their associatedlocations may be quantified to determine where the user is touching orhovering his or her finger within the area of the touch pad 104. In someexamples, the first set of electrodes and the second set of electrodesare equidistantly spaced with respect to each other. Thus, in theseexamples, the sensitivity of the touch pad 104 is the same in bothdirections. However, in other examples, the distance between theelectrodes may be non-uniformly spaced to provide greater sensitivityfor movements in certain directions.

In some cases, the display 106 is mechanically separate and movable withrespect to the keyboard with a connection mechanism 110. In theseexamples, the display 106 and keyboard 102 may be connected and movablewith respect to one another. The display 106 may be movable within arange of 0 degrees to 180 degrees or more with respect to the keyboard102. In some examples, the display 106 may fold over onto the uppersurface of the keyboard 102 when in a closed position, and the display106 may be folded away from the keyboard 102 when the display 106 is inan operating position. In some examples, the display 106 may beorientable with respect to the keyboard 102 at an angle between 35 to135 degrees when in use by the user. However, in these examples, thedisplay 106 may be positional at any angle desired by the user.

In some examples, the display 106 may be a non-touch sensitive display.However, in other examples at least a portion of the display 106 istouch sensitive. In these examples, the touch sensitive display mayinclude a capacitance sensor that is located behind an outside surfaceof the display 106. As a user's finger or other electrically conductiveobject approaches the touch sensitive screen, the capacitance sensor maydetect a change in capacitance as an input from the user.

While the example of FIG. 1 depicts an example of the portableelectronic device being a laptop, the capacitance sensor and touchsurface may be incorporated into any appropriate device. Anon-exhaustive list of devices includes, but is not limited to, adesktop, a display, a screen, a kiosk, a computing device, an electronictablet, another type of portable electronic device, another type ofdevice, or combinations thereof.

In the example depicted in FIG. 1 , an antenna 112 is positionedproximate the touch pad 104. In the antenna 112 may be positioned in anyapproximate with respect to the touch pad 104. For example, the antennamay be positioned underneath the touch pad, to the side of the touchpad,

FIG. 2 depicts an example of a portion of a touch input component 200.In this example, the touch input component 200 may include a substrate202, first set 204 of electrodes, and a second set 206 of electrodes.The first and second sets 204, 206 of electrodes may be oriented to betransverse to each other. Further, the first and second sets 204, 206 ofelectrodes may be electrically isolated from one another so that theelectrodes do not short to each other. However, where electrodes fromthe first set 204 overlap with electrodes from the second set 206,capacitance can be measured. The touch input component 200 may includeone or more electrodes in the first set 204 or the second set 206. Sucha substrate 202 and electrode sets may be incorporated into a touchscreen, a touch pad, and/or swell detection circuitry incorporated intoa battery assembly.

In some examples, the touch input component 200 is a mutual capacitancesensing device. In such an example, the substrate 202 has a set 204 ofrow electrodes and a set 206 of column electrodes that define thetouch/proximity-sensitive area of the component. In some cases, thecomponent is configured as a rectangular grid of an appropriate numberof electrodes (e.g., 8-by-6, 16-by-12, 9-by-15, or the like).

As shown in FIG. 2 , the touch input controller 208 includes a touchcontroller 208. The touch controller 208 may include at least one of acentral processing unit (CPU), a digital signal processor (DSP), ananalog front end (AFE) including amplifiers, a peripheral interfacecontroller (PIC), another type of microprocessor, and/or combinationsthereof, and may be implemented as an integrated circuit, a fieldprogrammable gate array (FPGA), an application specific integratedcircuit (ASIC), a combination of logic gate circuitry, other types ofdigital or analog electrical components, or combinations thereof, withappropriate circuitry, hardware, firmware, and/or software to choosefrom available modes of operation.

In some cases, the touch controller 208 includes at least onemultiplexing circuit to alternate which of the sets 204, 206 ofelectrodes are operating as drive electrodes and sense electrodes. Thedriving electrodes can be driven one at a time in sequence, or randomly,or drive multiple electrodes at the same time in encoded patterns. Otherconfigurations are possible such as a self-capacitance mode where theelectrodes are driven and sensed simultaneously. Electrodes may also bearranged in non-rectangular arrays, such as radial patterns, linearstrings, or the like. A shield layer (see FIG. 3 ) may be providedbeneath the electrodes to reduce noise or other interference. The shieldmay extend beyond the grid of electrodes. Other configurations are alsopossible.

In some cases, no fixed reference point is used for measurements. Thetouch controller 208 may generate signals that are sent directly to thefirst or second sets 204, 206 of electrodes in various patterns.

In some cases, the component does not depend upon an absolute capacitivemeasurement to determine the location of a finger (or stylus, pointer,or other object) on a surface of the touch input component 200. Thetouch input component 200 may measure an imbalance in electrical chargeto the electrode functioning as a sense electrode which can, in someexamples, be any of the electrodes designated in either set 204, 206 or,in other examples, with dedicated-sense electrodes. When no pointingobject is on or near the touch input component 200, the touch controller208 may be in a balanced state, and there is no signal on the senseelectrode. When a finger or other pointing object creates imbalancebecause of capacitive coupling, a change in capacitance may occur at theintersections between the sets of electrodes 204, 206 that make up thetouch/proximity sensitive area. In some cases, the change in capacitanceis measured. However, in alternative example, the absolute capacitancevalue may be measured.

While this example has been described with the touch input component 200having the flexibility of the switching the sets 204, 206 of electrodesbetween sense and transmit electrodes, in other examples, each set ofelectrodes is dedicated to either a transmit function or a sensefunction.

FIG. 3 depicts an example of a substrate 202 with a first set 204 ofelectrodes and a second set 206 of electrodes deposited on the substrate202 that is incorporated into a touch pad. The first set 204 ofelectrodes and the second set 206 of electrodes may be spaced apart fromeach other and electrically isolated from each other. In the exampledepicted in FIG. 3 , the first set 204 of electrodes is deposited on afirst side of the substrate 202, and the second set 206 of electrodes isdeposited on the second side of the substrate 202, where the second sideis opposite the first side and spaced apart by the thickness of thesubstrate 202. The substrate may be made of an electrically insulatingmaterial thereby preventing the first and second sets 204, 206 ofelectrodes from shorting to each other. As depicted in FIG. 2 , thefirst set 204 of electrodes and the second set 206 of electrodes may beoriented transversely to one another. Capacitance measurements may betaken where the intersections with the electrodes from the first set 204and the second set 206 overlap. In some examples, a voltage may beapplied to the transmit electrodes and the voltage of a sense electrodethat overlaps with the transmit electrode may be measured. The voltagefrom the sense electrode may be used to determine the capacitance at theintersection where the sense electrode overlaps with the transmitelectrode.

In the example of FIG. 3 depicting a cross section of a touch pad, thesubstrate 202 may be located between a touch surface 212 and a shield214. The touch surface 212 may be a covering that is placed over thefirst side of the substrate 202 and that is at least partiallytransparent to electric fields. As a user's finger or stylus approachthe touch surface 212, the presence of the finger or the stylus mayaffect the electric fields on the substrate 202. With the presence ofthe finger or the stylus, the voltage measured from the sense electrodemay be different than when the finger or the stylus are not present. Asa result, the change in capacitance may be measured.

The shield 214 may be an electrically conductive layer that shieldselectric noise from the internal components of the portable electronicdevice. This shield may prevent influence on the electric fields on thesubstrate 202.

The voltage applied to the transmit electrodes may be carried through anelectrical connection 216 from the touch controller 208 to theappropriate set of electrodes. The voltage applied to the senseelectrode through the electric fields generated from the transmitelectrode may be detected through the electrical connection 218 from thesense electrodes to the touch controller 208.

FIG. 4 depicts an example of a touch screen as the touch inputcontroller. In this example, the substrate 202, sets of electrodes 204,206, and electrical connections 216, 218 may be similar to thearrangement described in conjunction with FIG. 3 . In the example ofFIG. 4 , the shield 214 is located between the substrate 202 and adisplay 400. The display 400 may be a layer of pixels or diodes thatilluminate to generate an image. The display may be a liquid crystaldisplay, a light emitting diode display, an organic light emitting diodedisplay, an electroluminescent display, a quantum dot light emittingdiode display, an incandescent filaments display, a vacuum florescentdisplay, a cathode gas display, another type of display, or combinationsthereof. In this example, the shield 214, the substrate 202, and thetouch surface 212 may all be at least partially transparent to allow thedisplay to be visible to the user through the touch surface 212. Such atouch screen may be included in a monitor, a display assembly, a laptop,a mobile phone, a mobile device, an electronic tablet, another type ofportable electronic device, or combinations thereof.

In some examples, an antenna positioned near a touch sensor may radiateradio frequency signals that are detectable by the touch sensor andthereby interfere with the touch or proximity measurements made with thetouch sensor. The shield 214 may block the signals from the antenna andother components within a laptop or other type of computing device.However, blocking the antenna signal with the shield restricts the spacethrough which the antenna can broadcast. Often, the antenna's signal isincreased to compensate because of the effects of the shield, which inturn increases the amount of energy needed to operate the computingdevice.

FIG. 5 depicts an example of a shield layer 500 of a touch pad stack.The shield may be used for a Wi-Fi antenna, a Near Field CommunicateAntenna (NFC), another type of antenna, or combinations thereof. Theshield layer 500 of FIG. 5 may be constructed to replace a typical solidor hatched shield. The shield layer 500 may have a shape constructed toshield the electrode junction areas of the touch sensor while notshielding the areas far from the junctions. The anti-node may be thearea between the electrodes that is farthest away from the electrodejunctions. In some cases, the shield layer 500 is constructed to blockantenna signals from reaching the electrode junctions while allowing theantenna signal to pass through the anti-node areas of the touch sensor.In the illustrated example of FIG. 5 , a number of vertical rows 502 ofshield material and horizontal rows 504 may be fashioned to lay underthe corresponding electrode. The shield material may include copper,aluminum, or other appropriate shielding material and may be etched,printed, or otherwise deposited on a substrate. As shown, the shieldlayer 500 specifically shields the mutual capacitance junctions (e.g.,junction 506) where the electrodes overlap, but leaves the center (e.g.,center 508) of each sensor cell open to allow radio frequencies to passthrough. Additionally, the patterned shielding is divided intoindividual cells that shield individual sensor junctions. In someembodiments, the shielding cells may be connected to reduce and/orminimize the induced current from an NFC antenna or the like and reducethe power of the NFC system. In some cases, the cells may be connectedradially, vertically, connected in other arrangements to reduce theinduced currents. The particular shapes and rectangular grid shown forshield layer in FIG. 5 are merely exemplary and other shapes andpatterns may be used.

For example, FIGS. 6-7 show other exemplary shapes and patterns that maybe used in accordance with disclosed embodiments. FIG. 6 shows anembodiment of a shield layer 600 that has relatively smaller junctions606 and relatively larger open centers 608 and FIG. 7 shows anembodiment of a shield layer 700 that has relatively denser junctions706 and relatively smaller open centers 708. As a person of ordinaryskill in the art having the benefit of this disclosure would understand,other shapes, patterns, junctions, open centers, and the like may beemployed depending upon the functions and frequencies involved in aparticular processor-based device, touchpad, transceiver, and the like.

FIG. 8 depicts an example of a grid 800 of electrodes of the touchsensor. In this example, multiple transmit electrodes 804 are disposedon a substrate and orthogonally arranged with sense electrodes 806 alsodisposed on the substrate. The transmit electrodes 804 and the senseelectrodes 806 overlap with each other, but are electrically isolatedfrom each other, forming mutual capacitance intersections 808. In somecases, the electrical insulation is provided through the substrate, withthe transmit electrodes 804 being disposed on a first side of thesubstrate and the sense electrodes 806 being disposed on a second sideof the substrate. In some cases, as the voltage changes on a firsttransmit electrode, the capacitance on each sense electrode crossed bythe first transmit electrode changes at the intersection where theelectrodes cross. Further, when an electrically conductive objectapproaches the touch sensor, the mutual capacitance intersections nearthe object touching or approaching the touch sensor have changes intheir capacitance at these intersections.

In some examples, the surface of the touch sensor that is configured toreceive touch or proximity signals from a user is on a front,interfacing surface. The surface of the touch sensor that includes theshield near or on the opposite side or back side of the touch sensor.The shield structure may be disposed between the back surface of thetouch sensor and the antenna.

In the example of FIG. 8 , the shield structure includes an electricallyconductive material 810 that defines openings 812. The wireless signalstransmitted by the antenna can pass through the openings 812 defined inthe electrically conductive material 810. However, the portions of theelectrically conductive material 810 that remain may overlap with thetransmit electrodes 804, the sense electrodes 806, the mutualcapacitance intersections 808 between the transmit and sense electrodes,other portions of the touch sensor, or combinations thereof. In theillustrated example, the electrically conductive material 810 includesnarrow cross sectional width 814 that is aligned with the transmitelectrodes 804. At those regions of the shield structure that overlapwith the mutual capacitance intersections 808, the electricallyconductive material 810 includes in width and area forming a patternedshielding area 816 to provide more efficient shielding at the mutualcapacitance intersections. In this example, the patterned shieldingareas 816 are electrically connected in a vertical column 818 by thenarrow cross sectional widths 814.

FIG. 9 depicts an example of an electrically conductive material 810with narrow cross sectional widths 814 and patterned shielding areas 816overlapping at the mutually capacitive intersections. The openings 812are defined by the space between the vertical columns 818. In thisspecific example, portions of the sensor electrodes are not shielded bya portion of the electrically conductive material 810.

In the example of FIG. 10 , the patterned shielding areas 816 areradially connected with additional narrow cross sectional widths 814that overlap the sense electrodes forming a horizontal row 820. In thisexample, the openings are located between the vertical columns 818 andthe horizontal rows 820. In some examples, radially connecting thevertical columns may minimize the induced current and/or reduce theneeded power to transmit a wireless signal for some types of antennas.

FIG. 11 depicts a cross sectional view of a stack 900 with a touchsensor 901 and a shield structure 902. The touch sensor 901 may includea substrate 904. The substrate 904 may be any appropriate type ofsubstrate, such as a printed circuit board, fiberglass, an electricallyinsulating material, another type of material, or combinations thereof.On a first side 906 of the substrate 904, a first set 908 of electrodesmay be deposited. The first set 908 of electrodes may be transmitelectrodes, sense electrodes, or another type of electrodes. On a secondside 910 of the substrate 904 opposite of the first side 906, a secondset 912 of electrodes may be deposited. The second set 912 of electrodesmay be transmit electrodes, sense electrodes, or another type ofelectrodes. In this example, the first set 908 and the second set 912 ofelectrodes are orthogonal to each other.

Adjacent to the second set 912 of electrodes may be an electricallyinsulating material 914, and an electrically conductive material 916 maybe deposited on the far side 918 of the electrically insulating material914, opposite the second set 912 of electrodes.

The electrically conductive material 916 may shield certain portions ofthe touch sensor 901 from the radio frequencies emitted from an antenna.However, the electrically conductive material 916 may include openings920 that all the radio frequencies to pass through the shieldingmaterial.

In the example of FIG. 11 , the width of the electrically conductivematerial 916 overlapping with the mutual capacitance intersections is aswide as the electrodes in the first set 908. However, in the example ofFIG. 12 , the width of the electrically conductive material 916 is widerthan the width of the electrodes of the first set 908 of electrodes orwider than the mutual capacitance intersection. The width of theelectrically conductive material may depend on the tuning and/or otherelectrically characteristics of the antenna. However, width of theelectrically conductive material 916 may also vary throughout the touchsensor based on the proximity to the antenna.

In some examples, it may be desirable to have larger openings in theelectrically conductive material in those regions that are closer to theantenna. In such regions, the electrically conductive material 916 maycover less surface area allowing the openings to be larger therebyproviding a larger amount of space for the radio frequencies to passthrough. In those regions of the touch sensor that are located fartheraway from the antenna, the openings may be smaller with the electricallyconductive material 916 covering a greater amount of the touch sensor'ssurface area.

FIG. 13 depicts an example of touch sensor 901, a first antenna 1000,and a second antenna 1002. In this example, the touch sensor 901 has afirst region 1004, second region 1006, and a third region 1008. Thedashed lines 1003 and 1005 may generally represent boundary changesbetween the regions. The first region 1004 may be the closest to theantenna 1000, 1002, the second region 1006 may be the next closest tothe antennas 1000, 1002, and the third region 1008 may be located thefarthest away from the antennas 1000, 1002. In this example, theopenings in the shielding material of the first region 1004 may belarger than in the other regions thus the shielding material may coverless overall surface area in the first region 1004. In the second region1006, the shielding material may cover an increased amount of surfacearea making the openings smaller. In the third region 1008, the openingsmay be the smallest allowing the shielding material to cover even moresurface area than in the second region 1006. In some cases, the shieldmaterial in the third region 1008 may cover all the surface area withoutproviding openings.

FIG. 14 depicts an example of the boundary changes curving at the edgesof the touch sensor 901. In this example, the boundary changes mayreside at a predetermined distance from a surface of the antenna or anactive portion of the antenna. In this example, the ends of the antennasdo not reach the end of the touch sensor 901, thereby allowing thesecond and third regions 1006, 1008 of the touch sensor 901 to havegreater areas.

In the example of FIG. 15 , just a single antenna 1100 is depictedadjacent to the touch sensor 901. In this example, the antenna 1100resides along just a portion of the length of the touch sensor 901. Inthis example, the boundaries to the first region 1004 may decrease whilethe regions of the second region 1006 and third region 1008 mayincrease.

The touch sensor 901 may include any appropriate number of regions withdifferent amounts of shield material. For example, FIG. 16 depicts thatthe touch sensor 901 may include more than four regions 1004, 1006,1008, 1010, but more regions are included in other embodiments. In someexamples, just two regions may exist that have different amounts ofshielding.

Further, the geometries of those regions with varying amounts ofshielding may have different amounts of surface area. In the example ofFIG. 17 , the boundaries 1003, 1005 between the regions are irregular.In this example, the boundaries 1003, 1005 may be shaped to accommodatethe different characteristics of each antenna. For example, it may bedesirable for the first region 1004 to have more area based on theelectrical characteristics of the first antenna 1000, while it may bemore desirable for the first region 1004 to have less area due to thesecond antenna's electrical characteristics. Thus, the geometry of thedifferent regions may include having less area on one side of the touchsensor 901 than on the other side.

FIG. 18 depicts an example, where the amount of shielding based on theelectrical characteristics of the first antenna 1000 includes a largerarea with less shielding, but transitions more quickly to the secondregion 1006 with more shielding. On the other hand, the electricalcharacteristics of the second antenna 1002 may make it desirable to havea smaller area with less shielding proximate to the second antenna and alonger transition area to the regions with no openings in the shielding.While these examples have depicted touch sensors having specificconfigurations with varying amounts of shielding, any arrangements ofdifferent sizes and geometries of regions with varying amounts ofshielding may be used in accordance with the principles describedherein.

FIG. 19 depicts an example of a method 1900 of transmitting a signal.This method 1900 may be performed based on the description of thedevices, module, and principles described in relation to FIGS. 1-18 and20-32 . In this example, the method 1900 includes transmitting 1902 awireless signal through a shield structure of a touch sensor where theshield structure includes at least one opening in an electricallyconductive material that is large enough for the wireless signal to passthrough.

FIG. 20 depicts an example of a shield layer 2000. In this example, theshield layer 2000 includes a first thermal expansion groove 2002, asecond thermal expansion groove 2004, and a third thermal expansiongroove 2006. Each of the first, second, and third thermal expansiongrooves 2002, 2004, 2006 are generally aligned with each other. Each ofthese thermal expansion grooves 2002, 2004, 2006 have one end in a firstregion 2008 of the shield layer 2000 that is near a first side 2010 ofthe shield layer 2000. These grooves 2002, 2004, 2006 extend from thefirst region 2008 to a second region 2012 of the shield layer 2000 wherethe second region is near a second side 2014 of the shield layer 2000,where the second side 2014 is opposite to the first side 2010. Each ofthese grooves 2002, 2004, 2006 are made up of a plurality of segments2016. Each segment of the grooves 2002, 2004, 2006 is separated by atract 2018 of electrically conductive material. In some cases, theelectrically conductive material that forms the tracts 2018 is made ofthe same material that forms the rest of the shield layer 2000.

The shield layer 2000 depicted in the example of FIG. 20 also includes asecond set of grooves 2020 that are transversely oriented with respectto first set of grooves 2002, 2004, 2006. In some cases, the first setof grooves 2002, 2004, 2006 and the second set of grooves 2020 areorthogonally oriented with respect to each other. In some examples, thegrooves 2020 of the second set are also made up of segments 2016.

In some examples, the grooves 2002, 2004, 2006 in the first set areequidistantly positioned along the width of the shield layer 2000. Insome cases, the grooves 2020 of the second set are equidistantlypositioned along the length of the shield layer 2000. However, in someexamples, either set of grooves may not be equidistantly spaced withrespect to each other.

In some examples, each groove segment 2016 is a through opening thatgoes through the thickness of the material that forms the shield layer2000.

In the depicted example of FIG. 20 , the second set of grooves 2020intersect the first set of grooves 2002, 2004, 2006 through the tracts2018 between the segments 2016 of the second set of grooves 2020 andvice versa. In some examples, the shield layer 2000 may form a singlecontinuous shield that is connected at the tracts 2018. In otherexamples, the shield layer 2000 may include multiple independentportions that are divided by the thermal expansion grooves.

In cases, the thermal expansion grooves terminate near the sides 2010,2014, 2022, 2014 of the shield layer, but do not make contact with thesides 2010, 2014, 2022, 2024 of the shield layer 2000.

FIG. 21 depicts an example of a shield layer 2000 superimposed over atouch sensor 2100. This example depicts a first set of electrodes 2102that, although on a different layer of the touch sensor stack than theshield layer, are aligned with the first set of thermal expansiongrooves 2002, 2004, 2006 on the shield layer 2000. Further, this exampledepicts a second set of electrodes 2104 that, although on a differentlayer of the touch sensor stack than the shield layer, are aligned withthe second set of thermal expansion grooves 2020 on the shield layer2000.

In some examples, the touch sensor is more sensitive to capacitancechanges at or near the intersections between the first set of electrodes2102 and the second set of electrodes 2104. In contrast, in someexamples, the touch sensor may be less sensitive at or near theanti-node 2106 of the electrodes 2102, 2104. The anti-node may be themiddle location among adjacent electrode intersections on the touchsensor. For example, if an area of the touch sensor is enclosed by fourelectrodes that form four electrode intersections, the area may have asquare shape, and the anti-node may be located at or near the middle ofthe square-shaped area. In other examples, the area enclosed by theelectrodes may not be square-shaped. For examples, the area enclosed bythe electrodes may be rectangular shaped, polygonal shaped, rhombusshaped, symmetrically shaped, asymmetrically shaped, another kind ofshape, or combinations thereof. In some examples, the anti-node is alocation that is the farthest away from any of the electrodeintersections while still between multiple electrode intersections. Inyet another example, the anti-node may be the least electrode sensitivelocation between a set of electrodes.

In some examples, the intersection of the thermal expansion grooves onthe shield layer may be aligned at or near the anti-nodes on the touchsensor layers. In some cases, the thermal expansion grooves may crossunder an electrode of the touch sensor at a mid-point or near themid-point between the intersections of the electrodes on the touchsensor. In some examples, the thermal expansion grooves may cross atelectrode at the least electrode sensitive locations along the length ofthe electrode. In some cases, the thermal expansion grooves are alignedwith the electrodes, but offset from the electrodes.

The thermal expansion grooves may reduce stress in the touch sensorstack during the manufacturing process. In some cases, stress above acertain threshold may cause the shield layer to warp. Thus, by reducingthe temperature induced stress in the shield layer, warping may bereduced or eliminated. In some examples, when the electricallyconductive material of the shield layer (e.g., copper, nickel, gold,silver, etc.) is being bonded to a substrate and/or to the other layersof the touch sensor stack, the electrically conductive material of theshield layer may expand at a greater rate than the substrate or othermaterials used in the touch sensor stack. As a result, thermal stressmay build up between the electrically conductive material of the shieldlayer and/or the other layers of the touch sensor stack. In some cases,the stresses are present when the touch sensor stack or just portions ofthe touch sensor stack are at an elevated temperature. In some cases,the pressure is applied to the flat surfaces of the touch sensor stackto prevent warping due to the thermal expansion differences while thetouch sensor stack remains at an elevated temperature. However, with thethermal expansion grooves incorporated into the shield layer, the timethat such pressure has to be applied to the shield layer may be reduced,thereby speeding up the manufacturing process and reducing the overallcost of manufacturing the touch sensor stack.

In other examples, the thermal stress may build up when solderingcomponents to the touch sensor stack or performing other soldering taskson the touch sensor stack. At this stage of manufacturing, it may not bepossible to apply pressure to the shield layer. However, the localizedtemperatures induced from soldering may spread through the conductivematerial of the shield layer thereby heating other portions of the touchsensor stack. The thermal expansion grooves may reduce the amount ofheat that is spread throughout the touch sensor stack thereby reducingwarping. Also, as the conductive material of the shield layer expands,the material may expand into the grooves rather than inducing stressacross the entire surface of the shield layer. Thus, the thermalexpansion grooves of the shield layer may also prevent warping duringsoldering tasks performed on the touch sensor stack.

In some cases, the thermal expansion grooves not only reduce the stresswhile the touch sensor stack is under an elevated temperature during amanufacturing process, but the thermal expansion grooves may also reduceresidual stress that would have otherwise remained in the touch sensorstack even after the touch sensor stack cooled off.

The array of thermal expansion grooves may be evenly distributed andsynchronized with the capacitive sensor electrode pattern. In someexamples, the thermal expansion grooves may be located outside anelectrode effective area at or near the anti-node of the touch sensor. Anarrow area between electrode end point gaps may align to electrodeshorizontally and vertically. Connections between each groove end pointmay be synchronized with the sensor at an electrode pitch, an electrode½ pitch, an electrode ¼ pitch, another pitch, or combinations thereof.In some examples, groove connections at the end points may maintainuniform distribution across the shield layer. The thermal expansiongrooves may reduce the expansion of the shield layer when under a highertemperature during manufacturing.

FIG. 22 depicts an example where the tracts 2200 of a first thermalexpansion groove 2202 are offset from the tracts 2204 of a second,adjacent thermal expansion groove 2206. In some examples, the firstthermal expansion groove 2202 is aligned with the second thermalexpansion groove 2206.

FIG. 23 depicts an example of where at least some of the segments 2300of the thermal expansion grooves define an opening in the edges 2302 ofthe sides of the shield layer 2000. In some examples, the segments 2300defining the openings in the edges 2302 are transversely oriented withrespect to the edges 2302.

FIG. 24 depict an example where the segments 2400 of the thermalexpansion grooves have an ovular shape.

FIG. 25 depict an example where the segments 2500 of the thermalexpansion grooves have a slanted shape.

FIG. 26 depict an example where the segments 2600 of the thermalexpansion grooves have an alternating pattern of slanted shapes.

FIG. 27 depict an example where the segments 2700 of the thermalexpansion grooves have a wavy shape.

FIG. 28 depict an example where the segments 2800 of the thermalexpansion grooves have a curved shape.

FIG. 29 depict an example where the segments 2900 of the thermalexpansion grooves have a circular shape.

The device with the touch pad may be a laptop, a desk top, an externalpad for providing input to a computing device or to the cloud computingdevice, a computing device, a networked device, an electronic tablet, amobile device, a personal digital assistant, a control panel, a gamingdevice, a flat panel, a display, a television, another type of device,or combination thereof.

It should be noted that the methods, systems and devices discussed aboveare intended merely to be examples. It must be stressed that variousembodiments may omit, substitute, or add various procedures orcomponents as appropriate. For instance, it should be appreciated that,in alternative embodiments, the methods may be performed in an orderdifferent from that described, and that various steps may be added,omitted or combined. Also, features described with respect to certainembodiments may be combined in various other embodiments. Differentaspects and elements of the embodiments may be combined in a similarmanner. Also, it should be emphasized that technology evolves and, thus,many of the elements are exemplary in nature and should not beinterpreted to limit the scope of the invention.

Specific details are given in the description to provide a thoroughunderstanding of the embodiments. However, it will be understood by oneof ordinary skill in the art that the embodiments may be practicedwithout these specific details. For example, well-known circuits,processes, algorithms, structures, and techniques have been shownwithout unnecessary detail in order to avoid obscuring the embodiments.

Also, it is noted that the embodiments may be described as a processwhich is depicted as a flow diagram or block diagram. Although each maydescribe the operations as a sequential process, many of the operationscan be performed in parallel or concurrently. In addition, the order ofthe operations may be rearranged. A process may have additional stepsnot included in the figure.

Having described several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of theinvention. For example, the above elements may merely be a component ofa larger system, wherein other rules may take precedence over orotherwise modify the application of the invention. Also, a number ofsteps may be undertaken before, during, or after the above elements areconsidered. Accordingly, the above description should not be taken aslimiting the scope of the invention.

The invention claimed is:
 1. An apparatus, comprising: a touch sensor; the touch sensor having a first set of electrodes and a second set of electrodes that are electrically isolated from the first set of electrodes; a shield layer positioned adjacent to the touch sensor; and the shield layer having a plurality of thermal expansion grooves; wherein segments of the first thermal expansion groove are separated by tracts of electrically conductive material that form the shield layer; wherein a first thermal expansion groove is formed in a tract between segments of a second thermal expansion groove; an intersection between the first thermal expansion groove and the second thermal expansion groove that is aligned with an anti-node formed between the first set of electrodes and the second set of electrodes of the touch sensor.
 2. The apparatus of claim 1, wherein at least a first thermal expansion groove is transversely oriented with respect to a second thermal expansion groove.
 3. The apparatus of claim 1, wherein at least a first thermal expansion groove is segmented and extends from a first region proximate a first side of the shield layer to a second region proximate a second side of the shield layer, wherein the first side is opposite to the second side.
 4. The apparatus of claim 1, wherein a first set of tracts of the first thermal expansion groove are arranged to line up with a second set of tracts of a second thermal expansion groove, wherein the second thermal expansion groove is aligned with the first thermal expansion groove.
 5. The apparatus of claim 1, wherein a first set of tracts of the first thermal expansion groove are offset from a second set of tracts of a second thermal expansion groove, wherein the second thermal expansion groove is aligned with the first thermal expansion groove.
 6. The apparatus of claim 1, wherein at least one of the thermal expansion grooves aligns with an anti-node of the electrodes of the touch sensor.
 7. The apparatus of claim 1, wherein at least one of the thermal expansion grooves is offset from either the first set of electrodes or the second set of electrodes of the touch sensor.
 8. The apparatus of claim 1, wherein at least one of the thermal expansion grooves is formed in an edge of at least one side of the shield layer.
 9. The apparatus of claim 1, wherein a first set of thermal expansion grooves are aligned with each other and are substantially equidistantly spaced along a first dimension of the shield layer.
 10. The apparatus of claim 9, wherein a second set of thermal expansion grooves are aligned with each other and are substantially equidistantly spaced along a second dimension of the shield layer, wherein the second set of thermal expansion grooves are transversely oriented with respect to the first set of thermal expansion grooves.
 11. An apparatus, comprising: a touch sensor; the touch sensor having a first set of electrodes and a second set of electrodes that are electrically isolated from the first set of electrodes; a shield layer positioned adjacent to the touch sensor; and the shield layer having a plurality of segmented thermal expansion grooves; wherein segments of the first thermal expansion groove are separated by tracts of electrically conductive material that form the shield layer; wherein a first thermal expansion groove is formed in a tract between segments of a second thermal expansion groove; an intersection between the first thermal expansion groove and the second thermal expansion groove that is aligned with an anti-node formed between the first set of electrodes and the second set of electrodes of the touch sensor.
 12. The apparatus of claim 11, wherein at least the first thermal expansion groove is transversely oriented with respect to the second thermal expansion groove.
 13. The apparatus of claim 11, wherein segments of the first thermal expansion groove are separated by tracts of electrically conductive material that form the shield layer.
 14. The apparatus of claim 11, wherein at least one of the thermal expansion grooves aligns with an anti-node of the electrodes of the touch sensor.
 15. The apparatus of claim 11, wherein at least one of the thermal expansion grooves is offset from either the first set of electrodes or the second set of electrodes of the touch sensor.
 16. The apparatus of claim 11, wherein at least one of the thermal expansion grooves is formed in an edge of at least one side of the shield layer.
 17. An apparatus, comprising: a touch sensor; the touch sensor having a first set of electrodes and a second set of electrodes that are electrically isolated from the first set of electrodes; a shield layer positioned adjacent to the touch sensor; the shield layer having a plurality of thermal expansion grooves; a first thermal expansion groove of the plurality is transversely oriented with respect to a second thermal expansion groove of the plurality; the first thermal expansion groove is segmented and extends from a first region proximate a first side of the shield layer to a second region proximate a second side of the shield layer, wherein the first side is opposite to the second side; the segments of the first thermal expansion groove are separated by tracts of electrically conductive material that form the shield layer; the first thermal expansion groove is formed in a tract between segments of a second thermal expansion groove; and the first and second thermal expansion grooves aligns with an anti-node of the electrodes of the touch sensor. 